Social facts to society are like grammar to a language, a higher level of abstraction that is nonetheless real, as it governs the way things/words are ordered. You can speak a language without knowing anything about its grammar. Perhaps, that may affect the higher level of your command but you should mostly get by.
It is possible to deny the existence of social facts because they are not real in the sense of how physical things are real. It is never having been told about that that enabled Margaret Thatcher to claim, with a beady-eyed aplomb, that "there is no such thing as society". (The same woman insisted that a country finance is just like someone's purse: a deliberate lie or a misguided naiveté, we shall never know.) Some professional academics I know told me, very seriously, that identity, values and post-liberalism do not exist. They doubtlessly live according with their middle-classes values and various identities (class, gender, race, religion, etc.) in a very Neo-Liberal reality of latter-day London, yet since they have not been taught the grammar of (their own) social existence, they cannot quite put their finger on it. There is no vocabulary to talk about it and therefore it exists not: out of mind, out of sight. It is just like some of my students, very bright and eloquent young adults, who do not know a subjunctive clause from a parenthesis, because someone long time ago decided that teaching grammar at school is a waste of time, innit.
Learning grammar and learning social theory can and often do open up people's mind to a realisation that there is more to reality than just what is visible to the naked eye. As Castaneda's Don Juan wisely said, 'The true essence of the tree is between its leaves.' Without such an insight, one won't be able to see, metaphorically, the forest for the trees. Which automatically should disqualify anyone from any discussion about social matters. Unfortunately, that is still not the case, particularly where it matters: in politics and academia. Hence, we end up taught and led by people whose ability for mental abstraction and educated discussion does not exceed that of your average teenager.